The purpose of the study is to determine the effects on personality, particularly on level of functioning in vocational, academic, marital, social, and law-conforming areas, of sibling constellation, sibship size, sex of adjacent siblings, and sibling age-gap. Sibling-constellation, coping, and personal-cost data are being gathered by interview; some of the subjects also respond to the Minnesota Multiphasic Personality Inventory. Subjects being studied are 250 short-term neuropsychiatric patients, their parents and siblings; 150 college-going veterans and their parents, and siblings; 500 general-population families; 1400 long-term psychiatric inpatients, 3076 psychiatric outpatients. In the analysis, race, sex, ordinal postion among sibs, age, family size, intactness of family, and social class will be held experimentally constant before contrasting each personality measure for any two sibling constellations, such as oldest girls in families of three with a younger sister next, contrasted with oldest girls of three with a younger brother next. Computer-assisted contrasts between percentages, means and standard deviation, anova and manova, and regression analyses will be performed. BIBLIOGRAPHIC REFERENCE: Schubert, D. S. P., Wagner, M. E., & Schubert, H.J.P. One thousand references on sibling-constellation variables, J S P S Catalog of Selected Documents in Psychology, 1976, 6, in press. Schubert, D.S.P., Wagner, M.E., and Schubert, H.J.P. Creativity and Family constellation, Journal of Creative Behavior, 1976, 18, in press.